Police agencies from around the valley secure a perimeter after a fatal shooting of a Draper City police sergeant on Fort Street and approximately 13800 South in Draper early Sunday morning, Sept. 1, 2013. (Chuck Wing, Deseret News)

DRAPER — A series of 911 calls released Wednesday paint a picture of confusion and fear in a quiet Draper neighborhood on the morning Sgt. Derek Johnson was shot and killed.

The calls are short, as concerned residents asked for help and answers on Sept. 1, moments after Timothy Troy Walker, 35, opened fire, hitting Johnson and the woman travelling with him, Traci Lee Vaillancourt, 34, before shooting himself, police said.

"Get someone down here. There has been some shots fired," said a female caller, reporting she heard at least four shots. "There's a girl out there screaming. She's outside. I don't dare open the front door."

Police agencies from around the valley investigate a shooting on Fort Street and approximately 13800 South in Draper early Sunday morning, Sept. 1, 2013. (Chuck Wing, Deseret News)

Walker and Vaillancourt's car was broken down near 13200 S. Fort St. (850 East), damaged from driving through a nearby fence, when Johnson pulled up about 6 a.m., shattering the neighborhood's quiet Sunday morning.

"We just woke up to shooting sounds, and there were people screaming," said one woman. "My husband thinks he can hear a female and a male voice. They said, 'I have been shot.'"

Johnson was shot in his vehicle, which went off the road and crashed. One man called to tell dispatchers he could see the wrecked patrol vehicle from his house.

"It looks like it's actually a law enforcement vehicle that crashed," he said, adding that police were arriving.

With much still unknown, residents were told to stay in their homes as police began a manhunt through the area.

Police agencies from around the valley secure a perimeter around large area looking for suspects as they investigate a shooting on Fort Street and approximately 13800 South in Draper early Sunday morning, Sept. 1, 2013. (Chuck Wing, Deseret News)

"Just stay in your house at this time. We do have calls, and officers are on their way out there," a dispatcher told one man who called to report the gunshots.

Johnson was taken by medical helicopter to an area hospital, but was pronounced dead after arrival. Community members and law enforcement officers from across the state came together to remember the fallen officer, husband and father.

Upon his release from the hospital, Walker was booked into Salt Lake County Jail and charged with aggravated murder. He faces a potential death sentence if convicted.

Vaillancourt, who Walker allegedly shot in the back while she sat in the car with him, faces two obstruction of justice charges after her accounts of the shooting contradicted each other. An attorney says trauma has impacted her memory.